#ifndef MURMUR3_H
#define MURMUR3_H

//-----------------------------------------------------------------------------
// MurmurHash3 was written by Austin Appleby, and is placed in the public
// domain. The author hereby disclaims copyright to this source code.

// Note - The x86 and x64 versions do _not_ produce the same results, as the
// algorithms are optimized for their respective platforms. You can still
// compile and run any of them on any platform, but your performance with the
// non-native version will be less than optimal.

//-----------------------------------------------------------------------------
// Platform-specific functions and macros

// Microsoft Visual Studio

#if defined(_MSC_VER)

typedef unsigned char uint8_t;
//typedef unsigned long uint32_t;
typedef unsigned __int64 uint64_t;

// Other compilers

#else   // defined(_MSC_VER)

#include <stdint.h>

#endif // !defined(_MSC_VER)

#define FORCE_INLINE __attribute__((always_inline))

inline uint32_t rotl32(uint32_t x, int8_t r)
{
	return (x << r) | (x >> (32 - r));
}

#define ROTL32(x,y) rotl32(x,y)

#define BIG_CONSTANT(x) (x##LLU)

/* NO-OP for little-endian platforms */
#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__)
# if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#   define BYTESWAP(x) (x)
# endif
/* if __BYTE_ORDER__ is not predefined (like FreeBSD), use arch */
#elif defined(__i386)  || defined(__x86_64) \
	|| defined(__alpha) || defined(__vax)

# define BYTESWAP(x) (x)
/* use __builtin_bswap32 if available */
#elif defined(__GNUC__) || defined(__clang__)
#ifdef __has_builtin
#if __has_builtin(__builtin_bswap32)
#define BYTESWAP(x) __builtin_bswap32(x)
#endif // __has_builtin(__builtin_bswap32)
#endif // __has_builtin
#endif // defined(__GNUC__) || defined(__clang__)
/* last resort (big-endian w/o __builtin_bswap) */
#ifndef BYTESWAP
# define BYTESWAP(x)   ((((x)&0xFF)<<24) \
	| (((x) >> 24) & 0xFF) \
	| (((x)& 0x0000FF00) << 8)    \
	| (((x)& 0x00FF0000) >> 8))
#endif

//-----------------------------------------------------------------------------
// Block read - if your platform needs to do endian-swapping or can only
// handle aligned reads, do the conversion here

#define getblock(p, i) BYTESWAP(p[i])

//-----------------------------------------------------------------------------
// Finalization mix - force all bits of a hash block to avalanche

uint32_t fmix32_hideo(uint32_t h)
{
	h ^= h >> 16;
	h *= 0x85ebca6b;
	h ^= h >> 13;
	h *= 0xc2b2ae35;
	h ^= h >> 16;

	return h;
}

//-----------------------------------------------------------------------------

#ifdef __cplusplus
extern "C"
#else
extern
#endif
void MurmurHash3_x86_32(const void * key, int len, uint32_t seed, void * out)
{
	const uint8_t * data = (const uint8_t*)key;
	const int nblocks = len / 4;
	int i;

	uint32_t h1 = seed;

	uint32_t c1 = 0xcc9e2d51;
	uint32_t c2 = 0x1b873593;

	//----------
	// body

	const uint32_t * blocks = (const uint32_t *)(data + nblocks * 4);

	for (i = -nblocks; i; i++)
	{
		uint32_t k1 = getblock(blocks, i);

		k1 *= c1;
		k1 = ROTL32(k1, 15);
		k1 *= c2;

		h1 ^= k1;
		h1 = ROTL32(h1, 13);
		h1 = h1 * 5 + 0xe6546b64;
	}

	//----------
	// tail
	{
		const uint8_t * tail = (const uint8_t*)(data + nblocks * 4);

		uint32_t k1 = 0;

		switch (len & 3)
		{
		case 3: k1 ^= tail[2] << 16;
		case 2: k1 ^= tail[1] << 8;
		case 1: k1 ^= tail[0];
			k1 *= c1; k1 = ROTL32(k1, 15); k1 *= c2; h1 ^= k1;
		};
	}

	//----------
	// finalization

	h1 ^= len;

	h1 = fmix32_hideo(h1);

	*(uint32_t*)out = h1;
}

#endif